const fp = require('lodash/fp')
const { Maybe, Container } = require('./support')

// 练习1:
let maybe = Container.of([5, 6, 1])
let ex1 = (functor) => {
  return functor.map(v => fp.map(fp.add(1), v))
}
// console.log(ex1(maybe))

// 练习2:
let xs = Container.of(['do', 'ray', 'me', 'fa', 'so', 'la', 'ti', 'do'])
let ex2 = (functor) => {
  return functor.map(fp.first)._value
}
// console.log(ex2(xs))

// 练习3:
let safeProp = fp.curry(function (x, o) {
  return Maybe.of(o[x])
})
let user = { id: 2, name: 'Albert' }
let ex3 = (params) => {
  return fp.first(safeProp('name', params)._value)
}
// console.log(ex3(user))

// 练习4:
// let ex4 = function(n) {
//   if (n) {
//     return parseInt(n)
//   }
// }
let ex4 = (params) => {
  return Maybe.of(params).map(parseInt)._value
}
console.log(ex4(2.0))
